Image forming apparatus including adjustment processing and control method therefor

Abstract

Adjustment processing is suitably executed in accordance with the type of post processing. To accomplish this, an image forming apparatus includes, for example, an adjustment part, specifying part, and control part. The adjustment part performs at least one of adjustment operation for an image formation position and adjustment operation for an image formation density by forming adjustment patterns using a developing material on an image carrier and measuring the adjustment patterns. The specifying part specifies the size of an image to be formed on a sheet and the content of post processing in case of executing a job which requires post processing on the sheet. The control part controls, in accordance with the size of the image and the content of the post processing, whether to perform the adjustment operation by the adjustment part concurrently with the formation of an image made from a job requiring post processing.

1. An image forming apparatus comprising:
 an image carrier which carries an image formed by a developing material; 
 an adjustment part which performs at least one of adjustment operations for an image formation position and an image formation density by forming an adjustment pattern using a developing material on said image carrier and measuring the adjustment pattern; 
 a specifying part which, in case of executing a job which requires post processing for an image-formed sheet, specifies a size of an image to be formed on the image-formed sheet and a content of the post processing; and 
 a control part which controls whether to perform the adjustment operation by said adjustment part concurrently with formation of an image made from the job requiring the post processing, in accordance with the specified size of the image and the specified content of the post processing; 
 wherein said control part further comprises a decision part which decides, in accordance with the specified size of the image and the specified content of the post processing, whether processing of forming, on said image carrier, an image made from a job requiring post processing for the image-formed sheet, can be executed concurrently with adjustment operation by said adjustment part, and 
 wherein said control part operates said adjustment part concurrently with formation of the image made from the job requiring the post processing, or forms an image without operating said adjustment part, on the basis of a decision result obtained by said decision part. 
 
     
     
       2. An image forming apparatus claimed in  claim 1 , further comprising an image rotation part which rotates the image to secure a formation area for the adjustment pattern on said image carrier. 
     
     
       3. An image forming apparatus claimed in  claim 2 , wherein said decision part further comprises a distinguishing part which distinguishes whether the post processing can be executed even if said rotation part rotates the image to secure the formation area for the adjustment pattern on said image carrier. 
     
     
       4. An image forming apparatus claimed in  claim 3 , wherein one type of post processing which can be executed even if the image is rotated is one of a stapling process of stapling a sheet bundle and a shift process for sorting a plurality of sheet bundles. 
     
     
       5. An image forming apparatus claimed in  claim 3 , wherein one type of post processing which cannot be executed if the image is rotated is a punch process. 
     
     
       6. An image forming apparatus comprising:
 an image carrier which carries an image formed by a developing material; 
 an adjustment part which performs at least one of adjustment operations for an image formation position and an image formation density by forming an adjustment pattern using a developing material on said image carrier and measuring the adjustment pattern; 
 a specifying part which, in case of executing a job which requires post processing for an image-formed sheet, specifies a size of an image to be formed on the image-formed sheet and a content of the post processing; 
 a control part which controls whether to perform the at least one of adjustment operations by said adjustment part concurrently with formation of an image made from the job requiring the post processing, in accordance with the specified size of the image and the specified content of the post processing; and 
 a determination part which determines an execution timing for the at least one of adjustment operations on the basis of the number of image-formed sheets, wherein said control part executes the adjustment after interrupting image formation, if the at least one of adjustment operations cannot be executed concurrently with image formation when the determination execution timing has come. 
 
     
     
       7. An image forming apparatus comprising:
 an image carrier which carries an image formed by a developing material; 
 an adjustment part which performs at least one of adjustment operations for an image formation position and an image formation density by forming an adjustment pattern using a developing material on said image carrier and measuring the adjustment pattern; 
 a specifying part which, in case of executing a job which requires post processing for an image-formed sheet, specifies a size of an image to be formed on the image-formedsheet and a content of the post processing; 
 a control part which controls whether to perform the at least one of adjustment operations by said adjustment part concurrently with formation of an image made from the job requiring the post processing, in accordance with the specified size of the image and the specified content of the post processing; and 
 wherein said control unit interrupts image formation and executes the at least one of adjustment operations after images are formed on a reference number of sheets, in case of the job is a job for M sheets×N sets (M and N are natural numbers), and M exceeds a threshold. 
 
     
     
       8. A control method for an image forming apparatus which forms an image by using an image carrier for carrying an image using a developing material, comprising the steps of:
 in case of executing a job which requires post processing for an image-formed sheet, specifying a size of an image formed on the sheet and a content of the post processing; and controlling, in accordance with the specified size of the image and the specified content of the post processing, whether to perform adjustment operation concurrently with image formation of an image on the image carrier, the image is made from a job requiring post processing for a sheet on which the image is formed, and the adjustment operation is an operation of adjusting at least one of an image formation position and an image formation density by forming an adjustment pattern using a developing material on the image carrier and measuring the adjustment pattern; 
 wherein said controlling further comprises deciding, in accordance with the specified size of the image and the specified content of the post processing, whether processing of forming, on said image carrier, an image made from a job requiring post processing for an image-formed sheet, can be executed concurrently with said adjustment operation by said adjustment part; and 
 controlling said adjustment operation concurrently with formation of the image made from the job requiring the post processing, or forming an image without adjustment, on the basis of a decision result obtained by said deciding.